82 ANDEIOUS GLOBULI. 



hind tibias infuscated. Moderately shining, the mesonotum shagreened 

 throughout ; mesopleurse more or less striolate, the twelfth and 

 thirteenth antennal joints clearly longer than broad ; the apical joints 

 scarcely thickened. 



The $ is similar in coloration. 



Length 2 mm. 



May be known from curvator by the less shining 

 mesonotum, which is shagreened uniformly all over; by 

 the less thickened antennae (towards the apex), of 

 which the joints are all longer than broad ; and by 

 the striated mesopleurse. 



The gall-fly emerges in June. 



Forms a swelling on the terminal twigs of oaks 

 10 — 15 mm. in length, of somewhat irregular form, 

 smooth and green when young, becoming black or 

 dark brown when old, the surface then becoming 

 irregular. The internal cavity is longish, narrow, of 

 nearly equal width, and has the small, loose, ovoid 

 inner gall at its bottom, the cavity not being much 

 wider than the inner gall, and at the top at least is 

 lined with a membrane. The gall originates in a 

 terminal bud, and when the fly quits the gall in June 

 the swelling still continues to grow, and may become 

 surrounded with leaves or twigs. 



Curvator, it may be noted, forms terminal swellings 

 like those of inflator ; but these are seldom so elon- 

 gated, and the internal cavity is larger, and more 

 particularly wider. 



The parasites bred from this species are Mega- 

 stigmus dorsalis, Torymus auratus, Fonsc. ; Decatoma 

 Neesi, Foer. (Griraud) ; Pterom,alus dissectus, Walk. 

 (Griraud); P. PJrichsoni, Rtz. (Griraud). 



The only inquiline is Sapholytus connatus, Htg. 

 (Mayr). 



Rare and local. 



Continental : Sweden, Switzerland, Grermany, Aus- 

 tria. 



